The present invention relates to an optical information recording and reproducing apparatus which records the information in or reproduces the information from an optical information recording medium, such as an optical disk, by means of an optical head, and more particularly relates to an arrangement of components of the optical information recording and reproducing apparatus for effectively preventing dust from adhering to the optical head.
An optical disk drive can record more than 1 GB of data in an optical disk with a diameter of 13 cm (5.25 inches) or 30 cm (12 inches) and is becoming widely used as a memory apparatus for electronic files or picture processing systems.
The optical disk drive is advantageous in that the optical disk is a recording medium with a large capacity and is exchangeable. To exchange the recording medium, a front loading mechanism as disclosed in Japanese Patent Unexamined Publication No. 63-282955 is adopted. The optical disk is encased in an optical disk cartridge for preventing the information recording surface thereof from being exposed to the atmosphere and for ease of handling.
In the optical disk drive according to the prior art, an optical disk cartridge encasing therein an optical disk is mounted on a turntable, which is rotated by a spindle motor, by a loading mechanism. An optical head which records information to and reproduces information from the optical disk is radially movably carried on an optical head supporting portion. The optical head is moved along the optical head supporting portion by a linear motor. The displacement of the optical head is detected by a linear encoder and the moving speed thereof is detected by a speed sensor. A base which supports these mechanisms is supported on a frame through vibration insulating rubber members. The optical disk drive is further provided with a power supply, a cooling fan and a board package mounting electronic circuits to control the mechanisms.
The optical disk drive according to the prior art has a drawback in that dust adheres to optical parts including the optical head in a case where ambient air which contains the dust is sucked into the frame by the cooling fan when the optical disk is rotated within the optical disk cartridge to perform the recording or reproducing of information. Thus, the conventional optical disk drive has a problem in that an error may take place in recording information in or reproducing information from the optical disk due to lack of quantity of light by the adhesion of dust. It has been found that the adhesion of dust is mainly caused by the accumulation of dust contained in ambient air on the lens of the optical head. The ambient air is supplied to the board package and the power source which need cooling.